Just to add to this, Ive got a manual 143 se tech, 12 reg.
The trip computer at the moment reads 42mpg average over 3500 ish miles, which i guess isnt too bad.
Id say that was around 70% motorway and rest in various town driving.
When i use it for work i get between 25 to 32 mpg with start/stop traffic, however its only a short trip of around 4 miles so it doesnt even get warm.
the most ive ever seen in town was 39.9 driving like miss daisy at midnight with no traffic and mostly green lights.
Motorway driving I get very inconsistent results, ive driven from north devon to se london and managed 57mpg average.
Ive also driven from Edinburgh to se london again and only got 47mpg.
I generally drive between 60-70mph with cruise control, i have tried to do it manually but i struggle to beat the computer at this.
I must admit i love the car to bits but the engine seems very poor, my last car was a 2009 leon fr 170, which would get a consistent 35 to 50mpg in town and 50 to 62mpg motorway driving.
One thing to note, my leon, the trip computer did not calculate the average mpg when at a standstill, however i noticed the exeo computer does, which i guess is more accurate, which also would explain the differences in the lower than expected town driving mpg, being stopped for even 30 seconds my mpg can drop from 35 to 33 dependant how long you've been driving for of course.